Yesterday the front caliper seized on, so I took it off and stripped it down took the pistons and rings out and cleaned it all. put it back together and it was fine but today there is very little front bake it's very spongey. I also cleanded the resevior out today and aswell and checked for leaks everywhere which there was none. But still the same spongey brake. ( it's almost non existant ) any ideas???
Daz
__________________
TO BE OLD AND WISE , FIRST YOU HAVE TO BE YOUNG AND STUPID
Almost sure to be air somewhere in the system. Bleeding the system can be a bit iffy and some riders swear that the brake lever held on (rubber band) over night allows the air to rise to the master cylinder and escape. It is also a good idea to use fresh fluid every time and to bleed by the nipple on the caliper initially to restore feel. Have you replaced all the bits that you took off? Are the pads within wear limits? Does the caliper slide freely on the pins? Is your fluid line in good nick? Are the connections to caliper and reservoir sound with no leaks or tell-tale signs? If it's the original rubber version then these can (and do) become deformed with pressure and sometimes balloon in use. HEL do reinforced brake lines. Martyn
Thanx Martyn. I used new fuid, I cleaned the pistons and put back all the original parts. replaced the pads.caliper looks to be sliding freely and returnig to the normal position. no leaks...someone said something about the seal in the break lever resevior. What do ya think? Cheers Daz
__________________
TO BE OLD AND WISE , FIRST YOU HAVE TO BE YOUNG AND STUPID
I'd try the cheapest first. When you put the bike away at night then pull the brake on (lever to throttle) and tie it there with wire/tape/elastic. Leave it there over night. In the morning check the fluid level in the master cylinder. If it's not gone down then release the brake lever and check again. If it needs topping up then top it up. Now pump the lever on and off to see if it has firmed up any. If it is still as bad as before then it points to air either held in the system or fluid passing the seals somewhere. It's now the time to consider the master cylinder repair kit, but try another air bleeding first and cross your fingers. If it gets to this stage with no pressure then it may be advisable to replace the master cylinder seals, the brake pipe complete together with all the washers and banjos and refilling with new fluid. Hopefully, somewhere along this procedure you will re-gain your brake - if not then it's the caliper and seals time. Good luck. Martyn
Thanx for the advice Martyn I tried all of the above and changed the brake fluid resevior and lever as a kit and that seems to of done the job. After market jobby but it looks the part all shiny and that.
__________________
TO BE OLD AND WISE , FIRST YOU HAVE TO BE YOUNG AND STUPID
Is it fixed? Try bleeding with the caliper off and level with the reservoir. Chock it so it doesn't push the pistons out. The fact that the line swoops up before it goes down to the wheel can cause a problem as it's only a small master cylinder piston and caliper so the flow from the lever pull is not enough to overcome any bubbles floating back up the line and settling in the top of the loop.
Worth a try. Especially if you've had the top end undone.
